Thermal Pad, Method for Fabricating Thermal Pad, Heat Dissipating Apparatus and Electronic Device

• US 20140116661A1
• Filed: 12/31/2013
• Published: 05/01/2014
• Est. Priority Date: 10/24/2012
• Status: Abandoned Application

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Xu, Yan, Tu, Yunhua
• Application Number:
  US14/145,490
• Publication Number:
  US 20140116661A1
• Time in Patent Office: Days
• US Class Current: 165/133
• CPC Class Codes: B23P 15/26 heat exchangers or the like making heat exchangers by methods covered by other subclasses B21D53/02
• CPC Class Codes: F28F 3/00 Plate-like or laminated elements; Assemblies of plate-like or laminated elements specially adapted for movement F28F5/00
• CPC Class Codes: G06F 1/20 Cooling means
• CPC Class Codes: H01L 23/373 Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
• CPC Class Codes: H01L 23/3733 having a heterogeneous or anisotropic structure, e.g. powder or fibres in a matrix, wire mesh, porous structures H01L23/3732, H01L23/3737 take precedence
• CPC Class Codes: H01L 23/3737 Organic materials with or without a thermoconductive filler
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 29/4935 Heat exchanger or boiler making

Abstract

A thermal pad includes: a thermally conductive sheet-like substrate, where the sheet-like substrate has a compressible porous mesh structure in a thickness direction; and a thermally conductive coating, where the coating is formed of a flexible organic compound, and the organic compound fills inside the sheet-like substrate or is coated on a surface of the sheet-like substrate, or the organic compound both fills inside the sheet-like substrate and is coated on the surface of the sheet-like substrate. In the thermal pad, the method for fabricating a thermal pad, the heat dissipating apparatus, and the electronic device provided in the embodiments of the present application, a thermally conductive flexible organic compound fills inside or is coated on a thermally conductive sheet-like substrate having a compressible porous mesh structure in the thickness direction.

Claims

1. A thermal pad, comprising:

a thermally conductive sheet-like substrate, wherein the sheet-like substrate has a compressible porous mesh structure in a thickness direction; and

a thermally conductive coating, wherein the coating is formed of a flexible organic compound,

wherein the organic compound fills inside the sheet-like substrate or is coated on a surface of the sheet-like substrate, or the organic compound both fills inside the sheet-like substrate and is coated on a surface of the sheet-like substrate.

2. The thermal pad according to claim 1, wherein a thermal conductivity of the thermal pad is greater than or equal to 3 watts per meter Kelvin (W/mK), wherein the thermal conductivity of the thermal pad falls within a range from 3 W/mK to 5 W/mK, wherein the thermal conductivity of the thermal pad falls within a range from 5 W/mK to 15 W/mK, or wherein the thermal conductivity of the thermal pad falls within a range from 15 W/mK to 30 W/mK.

3. The thermal pad according to claim 1, wherein a Shore hardness of the thermal pad is less than or equal to Shore A 60, or wherein the Shore hardness of the thermal pad is less than or equal to Shore OO 60.

4. The thermal pad according to claim 1, wherein a compressive stress of the thermal pad under a 50% compression rate is less than or equal to 100 pounds per square inch (psi), wherein the compressive stress of the thermal pad under a 50% compression rate is less than or equal to 150 psi, or wherein the compressive stress of the thermal pad under a 50% compression rate is less than or equal to 250 psi.

5. The thermal pad according to claim 1, wherein a thermal conductivity of the sheet-like substrate is greater than or equal to 2 watts per meter Kelvin (W/mK), or wherein the thermal conductivity of the sheet-like substrate falls within a range from 5 W/mK to 30 W/mK.

6. The thermal pad according to claim 1, wherein a porosity of the sheet-like substrate is greater than or equal to 50%, or wherein the porosity of the sheet-like substrate falls within a range from 80.0% to 99.8%.

7. The thermal pad according to claim 1, wherein the porous mesh structure of the sheet-like substrate is made of a metal material or a carbon material.

8. The thermal pad according to claim 7, wherein the sheet-like substrate is an expandable graphite sheet, a foamed metal sheet, or a graphene foam sheet.

9. The thermal pad according to claim 1, wherein a thermal conductivity of the organic compound falls within a range from 0.5 watts per meter Kelvin (W/mK) to 6 W/mK, or wherein the thermal conductivity of the organic compound falls within a range from 1 W/mK to 3 W/mK.

10. The thermal pad according to claim 1, wherein a Shore hardness of the coating is less than or equal to Shore OO 60, or wherein the Shore hardness of the coating is less than or equal to Shore OO 30.

11. The thermal pad according to claim 1, wherein a thickness of the coating that is coated on the surface of the sheet-like substrate falls within a range from 1 micrometers (μ

m) to 0.5 millimeters (mm).

12. The thermal pad according to claim 8, wherein the sheet-like substrate is an expandable graphite sheet, wherein a density of the expandable graphite sheet falls within a range from 0.1 grams per cubic centimeter (g/cm3) to 0.25 g/cm3, wherein a porosity of the sheet-like substrate falls within a range from 89.0% to 96.0%, and wherein the thermal conductivity of the thermal pad falls within a range from 5 watts per meter Kelvin (W/mK) to 25 W/mK.

13. The thermal pad according to claim 8, wherein the sheet-like substrate is a foamed copper sheet, wherein a porosity of the foamed copper sheet falls within a range from 90.0% to 98.0%, and a wherein pore size of the foamed copper sheet falls within a range from 90 pores per inch (PPI) to 120 PPI, or wherein the sheet-like substrate is a graphene foam sheet, wherein a porosity of the graphene foam sheet falls within a range from 80.0% to 99.8%, and wherein a pore size of the graphene foam sheet falls within a range from 90 PPI to 120 PPI.

14. A method for fabricating a thermal pad, comprising:

providing a thermally conductive sheet-like substrate, wherein the sheet-like substrate has a compressible porous mesh structure in a thickness direction;

providing a thermally conductive and flexible organic compound; and

using the organic compound to fill inside the sheet-like substrate or coat on a surface of the sheet-like substrate, or using the organic compound to both fill inside the sheet-like substrate and coat on the surface of the sheet-like substrate to form the thermal pad.

15. The method according to claim 14, wherein using the organic compound to fill inside the sheet-like substrate or coat on the surface of the sheet-like substrate, or using the organic compound to both fill inside the sheet-like substrate and coat on the surface of the sheet-like substrate to form the thermal pad, comprises:

winding or overlaying the sheet-like substrate to form a multilayer sheet-like substrate with a multilayer structure;

using the organic compound to fill inside the sheet-like substrate or coat on the surface of the sheet-like substrate, or using the organic compound to both fill inside the sheet-like substrate and coat on the surface of the sheet-like substrate to form a first thermal pad blank; and

cutting the first thermal pad blank along a heat conduction direction of the first thermal pad blank to form the thermal pad.

16. The method according to claim 14, wherein using the organic compound to fill inside the sheet-like substrate or coat on the surface of the sheet-like substrate, or using the organic compound to both fill inside the sheet-like substrate and coat on the surface of the sheet-like substrate to form the thermal pad, comprises:

using the organic compound to fill inside the sheet-like substrate or coat on the surface of the sheet-like substrate, or using the organic compound to both fill inside the sheet-like substrate and coat on the surface of the sheet-like substrate to form a second thermal pad blank;

winding or overlaying the second thermal pad blank to form a third thermal pad blank with a multilayer structure; and

cutting the third thermal pad blank along a heat conduction direction of the third thermal pad blank to form the thermal pad.

17. The method according to claim 14, wherein a thermal conductivity of the sheet-like substrate is greater than or equal to 2 watts per meter Kelvin (W/mK), or wherein the thermal conductivity of the sheet-like substrate falls within a range from 5 W/mK to 30 W/mK.

18. The method according to claim 14, wherein a porosity of the sheet-like substrate is greater than or equal to 50%, or wherein the porosity of the sheet-like substrate falls within a range from 80.0% to 99.8%.

19. The method according to claim 14, wherein the porous mesh structure of the sheet-like substrate is made of a metal material or a carbon material, or wherein the sheet-like substrate is an expandable graphite sheet, a foamed metal sheet, or a graphene foam sheet.

20. The method according to claim 14, wherein a thermal conductivity of the organic compound falls within a range from 0.5 watts per meter Kelvin (W/mK) to 6 W/mK, or wherein the thermal conductivity of the organic compound falls within a range from 1 W/mK to 3 W/mK.